What is a key principle of the Theory of Transfer in criminal investigations?

The Theory of Transfer, often associated with the work of Edmond Locard, emphasizes that when two objects come into contact with each other, there is always a transfer of material from one to the other. This principle is foundational in criminal investigations because it establishes that individuals who enter a crime scene will either leave behind or take away physical evidence. This could include trace evidence such as hair, fibers, or other materials that could link a suspect to a crime or the crime scene to the victim.

Understanding this principle helps investigators collect and analyze evidence effectively, as it highlights the importance of all types of materials left behind, not just those that are immediately obvious or easy to see. It ensures that investigators consider the potential for unnoticed transfers that could be crucial for linking individuals to criminal activity, making it a critical concept in forensic science and criminal justice.